I suspect that, in the ensuing 11 years, the OP has resolved whatever questions he had about going on in his training
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
Divemaster will not be an easy class and will require you not only to learn but also demonstrate that you have learned. If your just into taking classes why not just take classes, collect the cards and become a Master Diver. It will be alot easer than the Divemaster class, quicker and probly alot cheaper. If you just want to be a better diver check into a class design towards extended range Padi Dsat, Adv Nitrox etc..(Read as: will hold you to a higher standard in basic skills not mention the advanced diving such as deeper and longer BT etc.etc..).
Since you are into the Law you might also want to think about the liability issue that you may incure by being a dive professional and if that could impact you next time you go diving and there is an emergency.
FYI, just food for thought. I'm glad to hear that you have an interest in learning more. Your ponderance in learning might change my view of you in a positive way.
The OP hasn't said he wants to be a professional - he said he wants to do the Divemaster course. Being qualified as a DM and working as one are not the same, and the liability issues are no different than they would be for any diver if you were not working as one.
Are you sure? Over the years on SB many agree with you, many disagree, and many like me are unsure. Lawyers have posted that liability and the ability to successfully sue a "non working at the moment" DM depends on a lot of things.
Well, Canada and the UK are different places than the U.S. when it comes to lawsuits. No need to get into a big discussion here, but there have also been posts regarding NON PRO buddys and their responsibilities to one another when stuff has been agreed to. I don't know if I'd use the word "myths", but since neither of us are lawyers.....